1. Field of the Invention
This invention relates to an appliance used in orthodontic treatment. More particularly, the present invention relates to a bite opener for reducing overbite or excessive overlap of one jaw relative to the other.
2. Description of the Related Art
Orthodontic treatment involves movement of malpositioned teeth to orthodontically correct locations. Orthodontic treatment can greatly improve the patient""s occlusion so that the teeth""s function is enhanced during biting and chewing. Moreover, straightening of crooked teeth can dramatically enhance the patient""s appearance.
One type of problem that is sometimes faced during orthodontic treatment is the correction of deep overbites that occur in anterior regions (i.e., front regions) of the oral cavity. Deep overbites exist when the upper or maxillary front teeth overlap the lower or mandibular front teeth by an undue amount. It is normally desired to correct deep overbites when possible in order to improve the overall appearance of the patient""s dentition.
Deep anterior overbites can be corrected during orthodontic treatment by extruding the posterior teeth (i.e., teeth located in rear portions of the oral cavity on both sides of the dental arch, including the molar teeth and bicuspid teeth). However, a significant amount of force is normally placed on the patient""s posterior teeth during normal opening and closing movements of the patient""s jaws. For this reason, it is generally not feasible to attempt to shift the posterior teeth as a group by using springs or force-inducing wires, since the force exerted on the posterior teeth by the patient""s jaws is normally much larger than the force that could be applied by such springs or wires.
One technique for correcting deep anterior overbites involves the use of tiny appliances that are bonded to the lingual side of the patient""s upper teeth (i.e., the side of the patient""s upper teeth that face inwardly toward the patient""s tongue). These appliances, sometimes referred to as bite openers, have a contact surface that extends in a direction that is generally parallel to the occlusal plane (i.e., a reference plane that is generally horizontal when the patient is upright and extends between the biting surfaces of the upper jaw and the lower jaw). Often, the bite openers are bonded to the patient""s two upper central incisor teeth so that two contact surfaces are presented to the opposing, lower central incisor teeth when the patient""s jaws are closed.
The contact surfaces of bite openers function to prevent the jaws from fully closing such that the patient""s lower posterior teeth do not contact the upper posterior teeth when the lower incisor teeth engage the bite opener. The resulting space between the upper posterior teeth and the lower posterior teeth enables each posterior tooth to be extruded over time in directions toward the opposing tooth. In many instances, the posterior teeth will extrude sufficiently to contact each other again and reestablish occlusion after only six or eight weeks of use of the bite opener.
Examples of appliances for opening the bite and correcting deep overbites are described in U.S. Pat. Nos. 4,915,630 and 5,957,686. These types of appliances are favored by many practitioners because they are bonded to the teeth during treatment and issues of patient compliance are avoided. Removable appliances are also possible, but can significantly increase the overall length of treatment time if the patient does not cooperate and wear the appliance as instructed.
However, there is a continuing need in the art to improve existing appliances used in orthodontic treatment so that the practitioner""s efficiency can be enhanced wherever possible. It is also desirable to improve the functional characteristics of existing appliances, so that the appliances provide optimal results during the course of treatment.
The present invention is directed toward an improved orthodontic bite opener having features that enhance patient comfort during use and facilitate removal of the bite opener from the oral cavity at the conclusion of its use. In one embodiment of the invention, the bite opener has a channel between mesial and distal sections, so that the bite opener can be easily debonded from the lingual surface of the tooth by squeezing the mesial and distal sections together. In another embodiment, the bite opener has a soft bite plate that is positioned for contact with the occlusal tips of the opposing teeth when the patient""s jaws are closed. Optionally, the bite plate is detachable from a body of the opener.
In more detail, the present invention in one aspect is directed toward an orthodontic bite opener that comprises a base for mounting the bite opener on a lingual side of the tooth. The bite opener also includes a mesial section connected to the base and a distal section connected to the base. Each of the mesial section and the distal section has an occlusal surface portion that extends in a reference plane generally parallel to the occlusal plane when the base is mounted on a lingual side of the tooth. The mesial section is spaced from the distal section to present a channel therebetween. The channel extends in a generally occlusal-gingival direction and provides a space for movement of at least one section toward the other section in order to facilitate debonding the bite opener from the tooth.
Another aspect of the present invention is directed toward an orthodontic bite opener that comprises a base for mounting the bite opener on a lingual side of the tooth and a body connected to the base. The body has at least one occlusal surface portion that extends in a reference plane generally parallel to the occlusal plane when the base is mounted on a lingual side of the tooth. The body also has a mesial outer edge and a distal outer edge that converge toward each other as the base is approached in directions along the occlusal surface portion.
The present invention is also directed toward an orthodontic bite opener that comprises a base for mounting the bite opener on a lingual side of the tooth and a body connected to the base. The body has a mesial section, a distal section and a channel extending, in a generally occlusal-gingival direction between the mesial section and the distal section. The bite opener also includes a bite plate connected to the body. The bite plate has at least one occlusal surface portion that extends in a reference plane generally parallel to the occlusal plane when the base is mounted on a lingual side of the tooth. The bite plate is made of a material having a hardness that is less than the hardness of the body.
Another aspect of the present invention is directed toward an orthodontic bite opener that comprises a base for mounting the bite opener on a lingual side of the tooth, a body connected to the base and a bite plate. The bite plate includes at least one occlusal surface portion that extends in a reference plane generally parallel to the occlusal plane. The bite plate is detachably connected to the body.
These and other aspects of the invention are described in more detail below and are illustrated in the accompanying drawings.